As the trend has pushed structures in semiconductor devices to smaller and smaller sizes, different patterning techniques have arisen to produce these structures. These techniques include spacer defined double or quadruple patterning, (immersion) lithography (193i), extreme ultraviolet lithography (EUV), and directed self-assembly (DSA) lithography. Lithography may be combined with spacer defined double or quadruple patterning.
In these techniques it may be advantageous to transfer the pattern of the polymer resist to a hardmask. A hardmask is a material used in semiconductor processing as an etch mask with a good etching resistance and etching selectivity to produce small structures. The hardmask may be made from a silicon dioxide layer.
Spacers may also be used in semiconductor manufacturing to protect against subsequent processing steps and may be made from silicon dioxide.
Further silicon dioxide can be used to fill gaps in the structures of semiconductor devices.
It is therefore advantageous to produce a silicon dioxide layer.